Can bus terminating resistor arrangement

ABSTRACT

A mobile power source includes an electrical generator, a controller, a resistor, and a user-activated switch positioned on a control panel of the electrical generator, the user-activated switch is configured to move between at least a first position and a second position. In response to the user-activated switch being in the first position, the resistor is configured to act as a terminating resistor at one end of a controller area network (CAN) bus of a power generation system, and in response to the user-activated switch being in the second position, the resistor is configured to be prevented from acting as the terminating resistor of the CAN bus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/043,939, filed on Jul. 24, 2018, and entitled CAN BUS TERMINATINGRESISTOR ARRANGEMENT, which claims priority to U.S. Provisional PatentApplication No. 62/536,205, filed on Jul. 24, 2017, and entitled CAN BUSTERMINATING RESISTOR ARRANGEMENT, the contents of each of which isherein incorporated by reference in its entirety.

BACKGROUND

Portable power generation systems are often used to provide power inremote locations. In some cases, multiple generators must be usedtogether to provide the desired quantity of power. In these situations,it is desirable to connect the various generators to one another tocoordinate their operation.

SUMMARY

The present invention provides, in one aspect, a power generation systemincluding a controller area network (CAN) bus and a first power sourcehaving a first electrical generator, a first controller connected to theCAN bus, a first resistor, and a first user-activated switch. The powergeneration system also includes a second power source having a secondelectrical generator, a second controller connected to the CAN bus, asecond resistor, and a second user-activated switch. The firstuser-activated switch is in a closed position to terminate a first endof the CAN bus, and the second-user activated switch is in a closedposition to terminate a second end of the CAN bus.

The present invention provides, in another aspect, a method of adjustingcommunication between a plurality of power sources. The method includesconnecting a first power source and a second power source to a CAN bus,and configuring communication between the first power source and thesecond power source over the CAN bus by connecting a first resistor ofthe first power source to the CAN bus and connecting a second resistorof the second power source to the CAN bus. The method further includesconnecting a third power source to the CAN bus, and configuringcommunication between the first power source, the second power source,and the third power source over the CAN bus by disconnecting the secondresistor from the CAN bus and connecting a third resistor of the thirdpower source to the CAN bus.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a mobile power source.

FIG. 2 is a schematic illustration of a power generation systemincluding a plurality of mobile power sources.

FIG. 3 is a perspective view of a control panel of the mobile powersource of FIG. 1.

FIG. 4 is a schematic illustration of another embodiment of a powergeneration system that includes two CAN buses and a plurality ofassociated mobile power sources, though for clarity only one mobilepower source is illustrated.

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways.

DETAILED DESCRIPTION

FIG. 1 illustrates a mobile power source 14 (or generator assembly 14).The mobile power source 14 is typically used at locations whereelectrical power from the power grid is not available. The mobile powersource 14 includes a housing 15 and can be implemented as, for example,a mobile or a portable generator, a construction or rental generator, amobile light tower, or an onboard power generator. Although the mobilepower source 14 is shown to be mobile on a pair of wheels 16 andequipped with a trailer hitch 17, the mobile power source 14 may nothave wheels, or may have additional wheels. In other words, the powersource 14 is configured to be movable to a desired (or targeted)location for the generation of electricity (or electrical power).

The mobile power source 14 has a generator 18 mounted within the housing15 to generate electrical power. In other words, the generator 18 isoperable to output electrical power. The electrical power can be asingle phase or three phase alternating current (AC) electrical power ata desired voltage and frequency. The mobile power source 14 can alsoinclude one or more transformers (not shown) to facility an output ofcurrent at multiple desired voltages. In another example of embodiments,the power source 14 is configured to provide electrical power as adirect current (DC) power supply at a desired voltage.

With reference to FIG. 2, each power source 14 includes a prime mover 19operably connected to the generator 18. The prime mover 19 is an engine,and more specifically a reciprocating piston engine (e.g., an internalcombustion, compression-ignition engine, etc.). As such, the engine 19can include at least one piston 20 positioned within an associatedcylinder 21. The at least one piston 20 (or a plurality of pistons) isconfigured to reciprocate in the associated cylinder 21 to rotate adrive shaft 23. The drive shaft 23 is coupled to the generator 18, androtation of the drive shaft 23 drives the generator 18 to produceelectrical power. While the illustrated embodiment depicts the primemover 19 as a reciprocating piston internal combustion engine, in otherembodiments, the prime mover 19 can be any engine or motor suitable todrive the generator 18. An example of a prime mover is a diesel engine.The power source 14 can also be configured to be operated by a pluralityof different fuels (or fuel sources or multiple fuels). For example, inone embodiment, the power source 14 can operate on a first fuel sourceand a second fuel source, with the fuel sources being different fuelsources. Examples of suitable fuel sources can include, but is notlimited to, diesel fuel, propane, liquid propane, gasoline, kerosene,natural gas, or any other suitable fuel.

With continued reference to FIG. 2, each power source 14 includes acontroller 22 that is configured to control the operation of theelectrical generator 18. In some embodiments, the controller 22 can alsocontrol the prime mover 19 (e.g., controls the engine speed of the primemover 19, etc.), and/or an alternator on the prime mover 19. Thecontroller 22 can be implemented as a single controller or more than onecontroller (e.g., a first controller to control operation of theelectrical generator 18, a second controller to the prime mover 19,etc.). The illustrated controller 22 is a digital controller. In otherembodiments, the controller 22 is an analog controller. The controller22 is configured to communicate with other controllers and devices by,for example, communication on a Controller Area Network (CAN) bus. Asdiscussed in additional detail below, the controller 22 of one powersource 14 can communicate with a controller 22 of a second power source14 through the CAN bus.

With reference to FIG. 3, each power source 14 also includes a controlpanel 26 (or user accessible panel 26) that provides a user access tothe controller 22 for the associated power source 14. In the illustratedembodiment, the control panel 26 is a front panel positioned on a frontof the power source 14. In other words, the front panel 26 is accessibleby the user. The control panel 26 includes gauges 30 that indicate theoperational status of the power source 14 as well as controls 34 thatcan be used to vary the operation of the power source 14. In addition,electrical outlets 38 are positioned on the front panel 26, which allowsa user to attach one or more devices to the power source 14 to receiveelectrical power.

With reference back to FIG. 2, a power generation system 10 includes aplurality of mobile power sources 14 (or mobile electrical generationsystems 14). While FIG. 2 illustrates at least four power sources 14, inother embodiments, the power generation system 10 includes at least twopower sources 14. Multiple power sources 14 may be required, forexample, to provide electrical power at desired levels. In addition,with the plurality of power sources 14 coupled together in the powergeneration system 10, the power generation system 10 can operate with aportion of the generators 18 (i.e., fewer than all of the generators 18)and/or all of the generators 18. In other words, the number ofgenerators 18 that are operational at a given time (or given moment) canbe a function of the load on the power generation system 10. In lowsystem load conditions, fewer than all of the generators 18 can operateto meet load demand, while in high system load conditions, all of thegenerators 18 can operate to meet load demand. In addition, by operatingsome of the generators 18 with a less than maximum load, for example,less fuel is required to operate the prime movers 19 of all the powersources 14, resulting in improved (or optimized) efficiency of thesystem 10.

The power generation system 10 includes a CAN bus 42 that facilitatescommunication between the power sources 14. The CAN bus 42 provides forelectrical communication between the controllers 22 of each associatedpower source 14. Communication between the power sources 14 can includecontrol signals to determine which of the power sources 14 in the powergeneration system 10 should be operational at any given time. Inaddition, diagnostic and functional information related to theindividual power sources 14 can be communicated over the CAN bus 42. Tofacilitate proper operation of the CAN bus 42, terminating resistors 46are positioned at each end of the CAN bus 42.

To facilitate the proper placement of the terminating resistor 46 ateach end of the CAN bus 42, each power source 14 includes a resistor 46and a user-activated switch 50. The user-activated switch 50 is movablebetween an open position and a closed position. When the switch 50 is inthe closed position, the resistor 46 operates as a terminating resistorat one end of the CAN bus 42. When the switch 50 is in the openposition, the resistor 46 is not connected to the CAN bus 42. However,the controller 22 of the power source 14 remains connected to the CANbus 42 regardless of the switch 50 position. In particular, theuser-activated switch 50 is electrically connected in series with theresistor 46, and the user-activated switch 50 and the resistor 46together are connected across the CAN bus 42 when the switch 50 isclosed. In the illustrated embodiment, the switch 50 is a toggle switch.However, in other embodiments, the switch 50 can be any suitableuser-activated switch or actuator (e.g., a push-button, a rocker switch,a touch pad, etc.).

In some embodiments, the power generation system 10 can have two powersources 14. In these embodiments, both power sources 14 have theirrespective switches 50 in the closed position to properly terminate theCAN bus 42. In other embodiments, the power generation system 10 canhave more than two power sources 14. In these embodiments, the two powersources 14 at the ends (e.g., at physical ends, at electrical ends,etc.) of the CAN bus 42 have their switches 50 in the closed position toproperly terminate the CAN bus 42. Any other power sources 14 connectedto the CAN bus have their switches 50 configured in the open position toconfigure the CAN bus 42 to include two terminating resistors at the CANbus ends. The switch 50 is positioned on the control panel 26 of eachpower source 14 (see FIG. 3) to provide user access and facilitate aneasy transition between the open position and the closed position. Thisallows any power source 14 to be quickly and easily transitioned to anend power source 14 on the CAN bus 42.

With continued reference to FIG. 2, the power generation system 10 isillustrated with four power sources 14A, 14B, 14C, 14D, with each powersource 14 including its own resistor 46 and its own switch 50.Specifically, the power generation system 10 includes a first powersource 14A with a first controller 22A connected to the CAN bus 42, afirst resistor 46A, and a first user-activated switch 50A. The powergeneration system 10 also includes a second power source 14B with asecond controller 22B connected to the CAN bus 42, a second resistor46B, and a second user-activated switch 50B. The first user-activatedswitch 50A is in a closed position to terminate a first end 54 of theCAN bus 42, and the second user-activated switch 50B is in a closedposition to terminate a second end 58 of the CAN bus 42. Thus, the firstpower source 14A is a first end power source and the second power source14B is a second end power source of the CAN bus 42. The switches 50 ofthe non-end power sources 14 are all configured to the open position.Specifically, the power generation system 10 includes a third powersource 14C including a third controller 22C connected to the CAN bus 42,a third resistor 46C, and third user-activated switch 50C. The thirdcontroller 22C is connected to the CAN bus 42 at a position 62 locatedbetween the first controller 22A connection to the CAN bus 42 and thesecond controller 22B connection to the CAN bus 42. In particular, thethird user-activated switch 50C is in the open position to disconnectthe third resistor 46C from the CAN bus 42. Finally, the powergeneration system 10 also includes a fourth power source 14D including afourth controller 22D connected to the CAN bus 42, a fourth resistor46D, and fourth user-activated switch 50D. The fourth controller 22D isconnected to the CAN bus 42 at a position 63 located between the firstcontroller 22A connection to the CAN bus 42 and the second controller22B connection to the CAN bus 42. In particular, the fourthuser-activated switch 50D is in the open position to disconnect thefourth resistor 46D from the CAN bus 42.

It should be appreciated that while the power generation system 10illustrated in FIG. 2 includes four power sources 14A-14D connected tothe CAN bus 42, in other embodiments of the power generation system 10,at least two, and more specifically three or more power sources 14 (orgenerators) can be connected to the CAN bus 42. It should further beappreciated that any two of the power sources 14 can be configured toestablish the ends 54, 58 of the CAN bus 42 by actuating the associatedswitch 50 to the closed position to connect the resistor 46 to the CANbus 42. With the ends 54, 58 of the CAN bus established by two powersources, any number of additional power sources can be connected to theCAN bus 42 therebetween.

In operation, the user selects the number of power sources 14 needed fora particular application. Each power source 14 in the power generationsystem 10 is operated as desired to provide for optimal efficiency,while still delivering the necessary electrical power to meet a loaddemand. The switch 50A for the first power source 14A is set to theclosed position to place the resistor 46A in the circuit including theCAN bus 42 to terminate the first end 54 of the CAN bus 42. Eachsubsequent power source 14 (e.g., the third power source 14C, the fourthpower source 14D, and any additional N number of power sources 14, etc.)is connected to the CAN bus 42 with its switch 50 (e.g., switch 50C,50D, 50N, etc.) in the open position to configure the resistor 46 (e.g.,resistor 46C, 46D, 46N, etc.) so that it is not placed in the circuitwith the CAN bus 42. Finally, the second power source 14B positioned atthe other end of the CAN bus 46. The second power source 14B isconnected to the CAN bus 42 with the switch 50B set in the closedposition to place the resistor 46B in the circuit including the CAN bus42 to terminate the second end 58 of the CAN bus 42. To place theresistor 46 into the circuit in the proper configuration, the useractuates each switch 50 on the control panel 26 for each power source 14into the desired position. This allows the user to quickly and easilyconfigure the resistors 46 and the CAN bus 42 as necessary for desiredoperation using only the switch 50 on the control panel 26 of each powersource 14.

As such, a method of adjusting communication between a plurality ofpower sources 14 includes connecting a first power source 14A and asecond power source 14B to the CAN bus 42, and configuring communicationbetween the first power source 14A and the second power source 14B overthe CAN bus 42 by connecting a first resistor 46A of the first powersource 14A to the CAN bus 42 and connecting a second resistor 46B of thesecond power source 14B to the CAN bus 42. The method can furtherinclude adding a third power source 14C to the power generation system10. More specifically, the method includes connecting a third powersource 14C to the CAN bus 42, and configuring communication between thefirst power source 14A, the second power source 14B, and the third powersource 14C over the CAN bus 42 by disconnecting the second resistor 46Bof the second power source 14B from the CAN bus 42 and connecting athird resistor 46C of the third power source 14C to the CAN bus 42. Thethird power source 14C can be connected to the CAN bus 42 with theuser-activated switch 50C in the open position (and thus the third powersource 14C is not an end power source on the CAN bus 42). In otherembodiments, the third power source 14C can be connected to the CAN bus42 as an end power source on the CAN bus 42. As such, the user-activatedswitch 50C of the third power source 14C is positioned in the closedposition, while the user-activated switch 50A, B of one of the otherconnected power sources 14A, 14B is positioned in an open configuration.As such, the first and third power sources 14A, 14C are the ends of theCAN bus 42. The method can further include disconnecting the third powersource 14C from the CAN bus 42, and re-configuring communication betweenthe first power source 14A and the second power source 14B by actuationof the respective user-activated switches 50A, B. Moreover, the methodcan further include connecting a fourth power source 14D to the CAN bus42, and configuring communication between the first power source 14A,the second power source 14B, the third power source 14C, and the fourthpower source 14D over the CAN bus 42 by connecting the fourth powersource 14D to the CAN bus 42 between the power sources positionedbetween the first and second ends 54, 58 of the CAN bus 42.

With reference to FIG. 4, an alternative power generation system 100includes a first CAN bus 104, a second CAN bus 108, and a power source112 with a power source controller 116 coupled to both the first CAN bus104 and the second CAN bus 108. It should be appreciated that the powergeneration system 100 of FIG. 4 only illustrates a single power source112 (with portions removed for clarity) to focus on the multipleresistors 120, 124 that selectively connected to multiple CAN buses 104,108. Similar to the power generation system 10 of FIG. 2, the powergeneration system 100 includes at least two power sources 112 (or aplurality of power sources 112). In other words, FIG. 4 illustrates oneof at least two power sources connected to both the first CAN bus 104and the second CAN bus 108. The power source 112 includes a firstresistor 120 selectively coupled to the first CAN bus 104, and a secondresistor 124 (i.e., an auxiliary resistor) selectively coupled to thesecond CAN bus 108. As mentioned above, the power source 112 issubstantially the same as the power source 14, and only a portion of thepower source 112 is being illustrated in FIG. 4 for clarity. A switch128 is coupled to a control panel 132 of the power source 112 and isuser-activated. The switch 128 can be a single throw, double pole switchthat connects and/or disconnects the first resistor 120 to the first CANbus 104 and the second resistor 124 to the second CAN bus 108. In otherwords, a single actuation of the switch 128 connects or disconnects bothresistors 120, 124. In alternative embodiments, the power source 112includes two separate switches to independently control selection ofresistors into the two CAN buses 104, 108.

Although the invention has been described in detail with reference tocertain preferred embodiments, variations and modifications exist withinthe scope and spirit of one or more independent aspects of the inventionas described. Various features and advantages of the invention are setforth in the following claims.

What is claimed is:
 1. A mobile power source comprising: an electricalgenerator; a controller; a resistor; and a user-activated switchpositioned on a control panel of the electrical generator, theuser-activated switch is configured to move between at least a firstposition and a second position, wherein in response to theuser-activated switch being in the first position, the resistor isconfigured to act as a terminating resistor at one end of a controllerarea network (CAN) bus of a power generation system, and wherein inresponse to the user-activated switch being in the second position, theresistor is configured to be prevented from acting as the terminatingresistor of the CAN bus.
 2. The mobile power source of claim 1, whereinthe controller is configured to be connected to the CAN bus of the powergeneration system.
 3. The mobile power source of claim 1, wherein thepower generation system includes a plurality of mobile power sources. 4.The mobile power source of claim 1, wherein the user-activated switch iselectrically connected in series with the resistor.
 5. The mobile powersource of claim 1, wherein the user-activated switch is a toggle switch.6. The mobile power source of claim 1, wherein the controller isconfigured to be connected to the CAN bus of the power generation systemin response to the user-activated switch being in the first position orthe second position.
 7. The mobile power source of claim 6, wherein thecontroller is configured to communicate with at least one other mobilepower source connected to the power generation system by the CAN bus. 8.The mobile power source of claim 1, wherein in response to theuser-activated switch being in the second position, the resistor isconfigured to not be operably connected to the CAN bus.
 9. A mobilepower source comprising: an electrical generator; a controller; a firstresistor; a second resistor; and a user-activated switch positioned on acontrol panel of the electrical generator, the user-activated switch isconfigured to move between at least a first position and a secondposition, wherein in response to the user-activated switch being in thefirst position, the first resistor is configured to act as a terminatingresistor at one end of a first controller area network (CAN) bus of apower generation system, and the second resistor is configured to act asa terminating resistor at one end of a second CAN bus of the powergeneration system, and wherein in response to the user-activated switchbeing in the second position, the first resistor is configured to beprevented from acting as the terminating resistor of the first CAN bus,and the second resistor is configured to be prevented from acting as theterminating resistor of the second CAN bus.
 10. The mobile power sourceof claim 9, wherein the second resistor is an auxiliary resistor. 11.The mobile power source of claim 9, wherein the user-activated switch isa single throw, double pole switch.
 12. The mobile power source of claim9, wherein the controller is configured to be connected to the first CANbus and the second CAN bus of the power generation system.
 13. A mobilepower source comprising: an electrical generator; a controller; aresistor; and a user-activated switch positioned on a control panel ofthe electrical generator, the user-activated switch is configured tomove between at least a first position and a second position, wherein inresponse to the user-activated switch being in the first position, theresistor is configured to be electrically connected to a controller areanetwork (CAN) bus of a power generation system, and wherein in responseto the user-activated switch being in the second position, the resistoris configured to be electrically disconnected from the CAN bus.
 14. Themobile power source of claim 13, wherein the user-activated switch iselectrically connected to the resistor.
 15. The mobile power source ofclaim 13, wherein the user-activated switch is electrically connected tothe resistor in series.
 16. The mobile power source of claim 13, whereinin response to the user-activated switch being in the first position,the resistor and the user-activated switch are configured to beconnected to the CAN bus.
 17. The mobile power source of claim 13,wherein in response to the resistor being electrically connected to theCAN bus, the resistor operates as a terminating resistor at an end ofthe CAN bus.
 18. The mobile power source of claim 13, wherein thecontroller is configured to be connected to the CAN bus in response tothe user-activated switch being in the first position or the secondposition.
 19. The mobile power source of claim 18, wherein thecontroller is configured to communicate with a second controller of asecond mobile power source connected to the power generation system bythe CAN bus.
 20. The mobile power source of claim 13, wherein thecontroller is configured to control operation of the electricalgenerator.